This invention relates to a differential amplifier of the cascode type comprising a differential stage which comprises a first and a second transistor whose collector-emitter paths are connected to an active load and whose bases are connected to inputs of the differential amplifier, the active load comprising a third and a fourth transistor whose collector-emitter paths are connected to a first supply voltage terminal via a first resistor and a second resistor respectively and whose bases are connected to a reference voltage terminal.
Such amplifiers are widely known and used. A problem with these amplifiers is the relationship between linearity and supply voltage. For a given supply voltage it may be desirable to improve the linearity or, conversely, for a given linearity it may be desirable to reduce the supply voltage. Applicant's French Patent 2,640,094, filed on 6 Dec. 1988, proposes a solution to this problem.